Burglars are stealing passports from homes in the capital to help immigrants enter the UK illegally, a police chief said today.

Hundreds of officers today swooped on more than 40 homes in north London as part of the Metropolitan Police’s “total war” on burglars. The dawn raids in nine boroughs, including Barnet, Brent, Camden and Westminster, saw 27 people arrested and thousands of pounds in proceeds from burglaries seized.

The Standard joined police at a semi-detached house in Colney Hatch, Barnet, where an 18-year-old man was arrested on suspicion of burglary, ID document offences and proceeds of crime offences. The suspect, believed to be of Irish descent, was held after officers broke down the door at 5am. Two girls in an upstairs bedroom screamed in terror as more than a dozen Territorial Support Group officers stormed into the house.

A 24-year-old burglary suspect was not at home when police raided an 11th floor flat in Cricklewood later this morning, but he was arrested after being tracked down elsewhere in London.

Commander Mak Chishty, Link Commander for Barnet, considered a hot spot for burglaries in north London, said the operation was “a clear warning to all burglars that we will do everything in our power to catch and convict them”. He said burglars in London were increasingly targeting ID documents and smaller electrical items such as iPods rather than the TVs or video players they aimed for a decade ago.

He said: “Bank cards and cheques are being stolen as well as ID documents such as passports. This can cause a great deal of harm to victims, families and communities.

“At the extreme end a false passport can lead to someone being in the country who is not entitled to be there or where it is dangerous.

“There can be everything from fraud, which damages our economy, even small businesses, financial loss, personal loss, to people who have entered the UK on false pretences.”